The invention relates to a radiodiagnostic installation with a motor-adjustable table, a motor-adjustable primary radiation diaphragm, and an image intensifier television system for image reproduction.
Radiodiagnostic installations of this kind produce an x-ray picture of a patient on a television monitor. To select the particular radiated region for a roentgenogram, the patient table is moved under fluoroscopy into a desired position, in which the desired part of the patient is displayed. Also, the primary radiation diaphragm is adjusted in accordance with the dimensions of this part. Therefore, complicated and time-consuming adjustment and selection procedures are required before an x-ray picture is taken. In particular it is often necessary to repeatedly alternate operating procedures, i.e. first to adjust the table by respective motor control, then to actuate the diaphragm, then to correct the position of the table, and so forth.
It is the object of the invention to provide a radiodiagnostic installation of the initially mentioned kind which minimizes the adjusting procedures required before an exposure, in particular before an indirect exposure.
According to the invention, there is assigned to the monitor a light pen for the entry of certain sites on the monitor into a memory. A control circuit is connected to the memory for controlling the motors of the patient table, the control circuit being designed so that the table is centered relative to the particular site on the monitor to which the light pen points. To adjust the patient table for the next exposure, it suffices to mark the center of the next region desired with the light pen on the monitor, while the current patient region is displayed. Thereafter the patient table is automatically motor-adjusted so that the marked region lies in the center of the picture.
In a preferred embodiment of the invention a diaphragm control circuit is provided for control of the primary radiation diaphragm in accordance with the particular picture field selected by the light pen. With this feature, not only is the patient table moved into the correct position by the marking of the region of interest on the viewer, but the primary radiation diaphragm is also automatically motor-adjusted in such a way that the desired region is focused.